Cancer is a leading cause of death in the United States. Breast, lung and prostate cancer alone cost billions of medical dollars each year. Most treatments now available are quite toxic to the human body; side effects such as nausea, vomiting, hair loss and fatigue cause hesitance and fear in cancer patients facing such treatments. The present invention provides a relatively non-toxic and simple treatment for cancers. This invention discloses a method to treat cancers by administering a member of the tetracycline family (TCN).
The major cause of cancer morbidity and mortality in humans is metastatic disease. As a consequence, there has been much interest in the mechanisms involved in invasion of cells and metastasis. Several enzyme systems have been implicated in the metastatic process: metalloproteinases, cysteine proteases, and serine proteinases. Yagel, S.A. et al., 49 Cancer Research 3553 (1989), Dickson R. B., 41 J. Steroid Biochem. Molec. Biol. 389 (1992) and Zucker S. et al., 45 Cancer Research 6168 (1985). Inhibitors of metalloproteinases, especially of the collagenases, have been the focus of intense study. DeClerck A. et al., 52 Cancer Research 701 (1992).
TCNs have been shown in dental studies to suppress metalloproteinase activity in gingiva, bone and cartilage. Golub L. M. et al., 25 J. Periodontal Res. (1990) and Gomes B. C. et al., 40 Experentia 1273 (1984). A few studies on animals have indicated that minocycline, a TCN, can suppress tumor metalloproteinase activity in animals. Zucker S. et al., 75 (3) JNCI 517 (1985). Other studies in animals show suppression of angiogenesis upon administration of minocycline. Tamargo R. J. et al., 51 Cancer Research 672 (1991). In 1986, researchers investigated human renal and prostate cancer cell proliferation arrest upon administration of doxycycline, particularly focusing on the effect of doxycycline on mitochondrial function. van de Bogert et al., 6 Cancer Res. 3283 (1986).
The present invention discloses that growth, migration and enzyme activity of human cancer cells can be altered by administration of TCNs. This invention provides a simple, non-toxic treatment for cancers.